Search

Aim: To investigate the role of oxidative stress in regulating the functional expression of P-glycoprotein (P-gp) in mitochondria of D407 cells., Methods: D407 cells were exposed to different ranges of concentrations of H 2 O 2 . The mitochondrial location of P-gp in the cells subjected to oxidative stress was detected by confocal analysis. Expression of P-gp in isolated mitochondria was assessed by Western blot. The pump activity of P-gp was evaluated by performing the efflux study on isolated mitochondria with Rhodamine 123 (Rho-123) alone and in the presence of P-gp inhibitor (Tariquidar) using flow cytometry analysis. The cells were pretreated with 10 mmol/L N-acetylcysteine (NAC) for 30min before exposing to H 2 O 2 , and analyzed the mitochondrial extracts by Western blot and flow cytometry., Results: P-gp was co-localized in the mitochondria by confocal laser scanning microscopy, and it was also detected in the mitochondria of D407 cells using Western blot. Exposure to increasing concentrations of H 2 O 2 led to gradually increased expression and location of P-gp in the mitochondria of cells. Rho-123 efflux assay showed higher uptake of Rho-123 on isolated mitochondria in the presence of Tariquidar both in normal and oxidative stress state. H 2 O 2 up-regulated P-gp in D407 cells, which could be reversed by NAC treatment., Conclusion: H 2 O 2 could up-regulate the functional expression of P-gp in mitochondria of D407 cells, while antioxidants might suppress oxidative-stress-induced over-expression of functional P-gp. It is indicative that limiting the mitochondrial P-gp transport in retinal pigment epithelium cells would be to improve the effect of mitochondria-targeted antioxidant therapy in age-related macular degeneration-like retinopathy.

Objective: To investigate the effect of dexmedetomidine hydrochloride on inflammatory lung injury and phosphorylation of extracellular regulated protein (ERK1/2) in a rat model of ventilator-induced lung injury (VILI)., Methods: Thirty-six adult male SD rats were randomized into 3 groups (n=12) to receive a 4-h standard ventilation (group C, with tidal volume of 8 ml/kg and respiratory rate of 90/min), high-tidal volume ventilation (group H, with tidal volume of 20 ml/kg and respiratory rate of 50 /min), and high-tidal volume ventilation plus 0.5 µg·kg(-1)·h(-1) dexmedetomidine infusion (group D), with the maintenance of a positive end expiratory pressure (PEEP) of 0 cmH(2)O. After mechanical ventilation the rats were sacrificed to collect the lung lavage liquid and lung tissue to examine the pulmonary inflammatory changes and tumor necrosis factor-α (TNF-α) expression as well as the expressions of ERK1/2 and p-ERK1/2., Results: Groups H and D showed obvious lung injury and significant elevations of the total protein, WBC, MPO, TNF-α, and ERK1/2 phosphorylation as compared with those of group C. The rats in group D showed milder lung pathologies with significantly lower levels of phosphorylation of ERK1/2 and TNF-α compared with those in group H., Conclusion: Dexmedetomidine can significantly attenuate VILI, decrease the production of the inflammatory molecules, and inhibit the activation of ERK1/2, demonstrating a protective effect against VILI.

Objective: To observe the effects of morphine and pethidine on P-glycoprotein (P-gp) expression in mouse brain microvascular endothelial cells and investigate the role of nuclear factor-kappaB (NF-kappaB) signaling pathway in morphine-induced up-expression of P-gp., Methods: The mouse brain microvascular endothelial cell line (b.END3) was subjected to pre-incubation with NF-kappaB inhibitor PDTC (5 micromol/L) for 1 h followed by stimulation with morphine (1 microg/ml) or pethidine (1 microg/ml) for 24 h. The bEnd.3 cells were then collected for Western blotting for P-gp expression., Results: A 24-h morphine stimulation induced an up-expression of P-gp in bEnd.3 cells by almost 200%. Pethidine in similar conditions did not affect P-gp expression in the cells. PDTC, the specific inhibitor of NF-kappaB, inhibited morphine-induced up-expression of P-gp in the cells., Conclusion: Morphine can induce up-expression of endogenous P-gp in mouse brain microvascular endothelial cells. NF-kappaB signaling pathway is involved in the morphine-induced up-expression of P-gp.

Objective: To investigate the effects of micro-encapsulated bifidobacteria on gut barrier and bacterial translocation after hemorrhagic shock and resuscitation., Methods: Sprague-Dawley rats were divided into 6 groups: PBS+sham shock group fed with PBS for 7 days and then undergoing sham shock, bifidobacteria+sham shock group fed with bifidobacteria (10(9) cfu/d) for 7 days and then undergoing sham shock, micro-encapsulated bifidobacteria+sham shock group, fed with micro-encapsulated bifidobacteria (10(9) cfu/d) for 7 days and then undergoing sham shock, PBS+hemorrhagic shock group fed with PBS for 7 days and then undergoing hemorrhagic shock, bifidobacteria+shock group fed with bifidobacteria for 7 days and then undergoing hemorrhagic shock, and micro-encapsulated bifidobacteria+shock group, fed with micro-encapsulated bifidobacteria for 7 days and then undergoing hemorrhagic shock. Three hours after resuscitation laparotomy was performed, distal cecum was resected to undergo bacteriological analysis of the cecal content, mesenteric lymph nodes (MLNs), a liver lobe, and the middle part of spleen were resected to undergo bacterial culture for bacterial translocation, and the terminal ileum was resected to observe the villous damage., Results: There was no significant difference in the amount of blood loss among the 3 hemorrhagic shock groups. The amounts of aerobes in cecum of the bifidobacteria+shock and micro-encapsulated bifidobacteria+shock groups, especially that of the latter group, were significantly lower than that of the PBS+shock group. The amounts of anaerobes and the amounts of bifidobacteria in cecum of the bifidobacteria+shock group and micro-encapsulated bifidobacteria+shock group, especially those of the latter group, were significantly higher than those of the PBS+shock group. No bacterial translocation to liver was observed in all groups. The magnitudes of total aerobes translocation in spleen of the bifidobacteria+shock and encapsulated bifidobacteria+shock groups were significantly lower than that of the PBS+shock group, however, there were not significant differences in the translocation in the MLN of total aerobes ad bifidobacteria among different groups. The percentage of ileal villous damage of the bifidobacteria+shock and encapsulated bifidobacteria+shock groups were significantly lower than that of the PBS+shock group., Conclusion: Bifidobacteria effectively protects the gut barrier, reduces bacterial translocation from the gut after hemorrhagic shock and resuscitation. And micro-encapsulated Bifidobacteria can enhance those effects further.

Objective: To investigate the clinical effects of epidural clonidine pretreatment in epidural patient-controlled analgesia (PCA) using sufentanil combined with levobupivacaine., Methods: Sixty patients undergoing abdominal hysterectomy of ASA status I-II were randomly divided into 3 equal groups: C2 group was pretreated with epidural clonidine 2 microg/kg at the L2-3 interspace, 15 min later, epidural anesthesia was performed with 0.5% levobupivacaine, and then 0. 4 microg/ml combined with levobupivacaine 2 mg/ml was given for postoperative epidural patient-controlled analgesia. C4 group was pretreated with epidural clonidine 4 microg/kg, and C0 group was pretreated with normal saline. The analgesic effect, PCA drug dosage, adverse reaction, and visual analog scale (VAS) score were recorded., Results: Anesthesia was clinically satisfactory in all patients. The rate of atropine use of the C4 group was 30%, significantly higher than those of the C2 group (15% ) and C0 group (5%, both P < 0.05). The rate of VAS < or = 3 at rest 24 h postoperatively of the C2 and C4 groups were 88% and 93% respectively, both significantly higher than that of the C0 group (75%, P < 0.01 and P < 0.01). The rate of VAS < or = 3 while coughing 24 h postoperatively of the C2 and C4 groups were 61% and 79% respectively, both significantly higher than that of the C0 group (48%). The dosages of PCA drug of the C2 and C4 groups were significantly lower than that of the C0 group by 11.8% and 22.8% respectively (both P < 0.05). The dosage of PCA drug 0-4 h after operation of the C2 was significantly higher than that of the C4 group. The sedative degree of the C4 group was higher than that of the C0 group. The rate of postoperative vomiting of the C0 group was 40%, significantly higher than that of the C4 group (10%, P < 0.05)., Conclusion: Epidural clonidine 2-4 microg/kg pretreatment improves the clinical effects of epidural PCA using sufentanil combined with levobupivacaine.